The guys sitting behind me are thirtyish computer jockeys from Fairfax hanging at the ballpark, doing guy things -- drinking beer, downing sausages, ogling the ladies. So does it matter that they have no clue what's happening on the field?

One gent carefully explains to his friend that a ball hit to the infield is a single and a ball to the outfield is a double. Aargh!

This summer's new joy is the large, enthusiastic showing at RFK Stadium, a nightly celebration of baseball's return to Washington. But it's becoming clear that 33 years without the sport left a gaping hole in our collective knowledge of the game. Hard-core fans never let their passion lapse, but generations grew up here with little or no exposure to baseball.

The Nationals aren't likely to offer introductory clinics on their sport. Maybe they should hire Paul Dickson of Garrett Park and similarly knowledgeable fans and sprinkle them throughout the ballpark.

I'm a lifelong fan but a total novice compared with Dickson, the author of 45 books, five of them on baseball, including The Dickson Baseball Dictionary (a "fandango" is a strikeout) and volumes on the subtleties of the game.

I invited Dickson to a Nats game to show me what the average fan might miss. His new book, "The Hidden Language of Baseball," describes how to spot and interpret the signs players and coaches flash during the game. The key: Watch the players, not the ball.

"TV trains us to watch the ball, but you need to see how the outfielders move around, where the infielders are positioned," Dickson says. About 1,000 signs are used over the course of a game. The shortstop and second baseman signal each other about who will cover second with a man on first. (An open mouth might be one player's signal.) Runners on second use their feet to let the batter know what they've gleaned about the next pitch; crossed feet might mean one kind of pitch, a little shuffle might mean another.

The late Yankees broadcaster Red Barber advised fans to develop their sense of baseball by focusing on a single player for an entire game; for example, watch the third baseman to see how he moves on every play, especially those on which he is not directly involved.

Bring binoculars and you can home in on interactions between the dugout and the field. When you see the batter step out of the batter's box and knock dirt out of his cleats, that could be a sign -- either the batter has not understood his instructions, or he doesn't want to do as he's been told.

As in poker, baseball players search for "tells" -- the positioning of an elbow or a foot that gives away a pitcher's intentions about his next pitch. Ty Cobb's teammates knew that the consummate hitter licked his upper lip before attempting to steal a base.

Dickson watches for all this even as he scores the game -- the subject of another of his books. Scoring is less common at RFK than at many other parks; this is another tradition that flagged during our decades in the baseball desert. But Dickson is optimistic that the art of scoring will make a comeback: "You're writing your own libretto. It's a way of getting into the game, and it's the only true souvenir." Dickson saves his scorecards; he even occasionally scores off TV at home. At RFK, it's mostly old guys who score, but I've also seen kids and women hunched over their little boxes.

Dickson inherited his fascination with the game from his father, and he has passed the fever on to his son, who years ago at Memorial Stadium in Baltimore peppered Dad with questions: "Why is he called the shortstop? Why do they call it a bunt?"

That inspired Dickson's Baseball Dictionary, a compendium of 5,000 definitions of baseball terms and expressions, from "ain't the beer cold" (Orioles broadcaster Chuck Thompson's all-purpose phrase for any excellent development on the field) to "yakker" (a sharp-breaking curveball, derived from a name for a woodpecker).

That book led to a collection of baseball quotations, from Branch Rickey's "A full mind is an empty bat" to Yogi Berra's "Why buy good luggage? You only use it when you travel."

"Baseball plays out like an opera," Dickson says. "You have your characters -- bad guys and the lovable, prodigal son. It's a great drama, different every night." And finally, it's ours to keep (even if Peter Angelos has made sure it's not on TV).